Electron discharge device



J. E` CLARK ET AL EEECTRON DISCHARGE DEVICE Filed NOV. l, 1934 F/G. l

/Nl/ENTORS! A TTOR/VEY Patented Dec. 27, 1938 l l YSTTES PATENT OFFICE ELEc'rRoN DISCHARGE DEVICE Application November 1, 1934, Serial No. 750,928

14 Claims.

This invention relates toV electron discharge devices and more particularly to such devices capable of yielding a high power output.

One object of this invention is to construct an electrode assembly for a discharge device to withstand excessive vibrations and sudden shocks.

Another object of the invention is to form a compact assembly of the electrodes so that the spacial relation between the electrodes is constantly uniform.

According to the invention, the electrode assembly inclues an anode of high heat conserving material which encloses the other electrodes and is provided with projecting portions on opposite sides which accommodate the supporting .members of the assembly to form a compact, 'unitary mount. An insulating member extends across each end of the anode to accurately space the cathode and a grid within the anode. The insulating members are secured to the anode by rigid rods enclosed in the projecting portions of the anode and these rods are connected to truss members which are joined to cooperating converging braces or supporting members which extend from the stem of the device and exert Aa compression force on opposite sides of each projecting portion of the anode. The electrode unit or mount is therefore rigidly held in position with the braces locked in the sides of the anode structure.

A feature of the invention relates to a unit assembly which avoids distortion or breakage of the fragile filament during extreme heat treatment of the assembly due to expansion. This is 35Y accomplished by connecting the truss member to the end of the internal rigid rods in the anode to allow a clearance between the lower spacing insulator and the truss members. This arrangement permits the unit structure to expand dur- 40 ing the high temperature heat treatment to remove occluded gases and equalizes the stresses in the lament supporting members to overcome distortion and displacement of the filament in relation to the other electrodes.

Another feature of the invention is concerned Vwith an assembly of the lament supports in order to damp out peak stresses either-from shocks or excessive temperatures which adversely affect the alignment of the lament supports. In accordance with this invention, the filament leading-in wires extend parallel from the press and are connected to rigid wires angularly arranged. above the lower spacer insulator. ends of the lament are connected to light hook ,members whichare arrangedto form continua- The.

(Cl. Z50-27.5)

tions of the `ilamentary strand and are attached to the rigid wires at the termination of the angular line of the filament.

A further feature of the invention relates to the supporting structure of the anode whereby sudden shocksapplied to the device will not fracture the friablematerial of the anode. This arrangement consists in an assembly of the anode and the internal support rods in such a manner that the rods are unconned for a portion of their length to obtain a certain degree of resiliency in the structure adjacent the junction of the internal supporting rod and the spacer insulator. This assembly eliminates strains in the anode material in the immediate Vicinity of the bisecting members of the metallic supporting structure.y

Another feature of the invention relates to the mounting of the electrode assembly on the stem of the device Vso that the unit is rigidly held and deflection inthe supporting structure due to the large mass of electrode unit is eliminated by anchoring the unit to the stem at an intermediate point. This arrangement consists of a single band attached to the braces at the extreme end ,'25 and surrounding the glass stem while the anchoring rods projecting from the top of the stem register with the lower insulator of the electrode assembly to maintain the unit in rigid position and offset deection in the long braces connectring the electrode unit to theV stem. Another advantage of this arrangement is the protection of the glass stem against excessive heating during the exhausting process of the device Yby high frequenoy'induction due to the advancement of 35 the circular metallic band around the stem to the extreme end of the stern where it is removed from the effects of the high frequency eld.

These and other features of the invention will be more clearly understood from thefollowing 40 detailed description taken in connection with the accompanying drawing:

Fig. 1 illustrates in a perspective view a discharge device embodying the features of this invention and having'a portion of the enclosing 45 vessel and the anode broken away to more clearly illustrate the details of the construction;

Fig. 2 shows in elevation a side View of the electrode unit and the relation of the brace supports to thejanode;

Fig. 3 is a perspective view` of the stem and ksupporting braces without the electrode unit;. e Fig. 4 is'a perspective view of the details of the bottom insulator arrangement shown in Fig. 55

1 which also illustrates the anchoring rods in the press registering with the insulator; and

Fig. 5 is a cross-sectional view of a portion of the anode taken on the line 5-5 in Fig. 2 and showing the prongs of the braces extending through the anode flange.

Referring'to the drawing, the device of thisVV invention as shown in Fig. 1, includes an enclosing vessel I having an inwardly projecting stern II terminating in a press I2. The Vessel is secured to a base I3 carrying a plurality of prongs or terminals I4 for connecting the electrodes to an external circuit. A plurality of strong rigid wires or anchoring members I5, I6 and I'I are sealed through the press I2 and extend above the press for a short distance to serve as anchors for the electrode assembly While the opposite ends are connected to leading-in wires which terminate at the prongs I4 in the base I3.

The electrode assembly on the stem of the vessel may conform to the specific aspect of the invention illustrated, but it is to be understood that the invention is not limited to the precise Vconfiguration ofthe elements nor the manner in which they are assembled in the following description since it is-within theiscope of this invention to apply the features of' the invention to other electrode units radically different from the specific unit illustrated. Therefore, the succeeding disclosure is merely a representative embodiment of the invention and theI manner in which it may be applied to a particular aggregation of elements.

The unit, as illustrated, may be assembled Yby placing a cross-shaped insulator I8 on the wires I5, I6 and I'I, the insulator having a plurality of apertures along one of its arms to correspond `with theposition of the short wires in the press so that these wires may project through the apertures and form anchors for the insulator.V

wires by welding the ends of anchor wires I6 and I1 projecting above the insulator to connector wires 28 and 2| which extend in opposite directions above the insulator to form spacers for Vhooks 22, the connector 20 being longer than the connector 2I in order to space the hooks attached thereto at an equal distance from the 'center of the insulator I8. A tie wire 23 extends through the insulator I8 and is connected to the midpoint of the connector 20 to maintain this wire in rigid position. A central hook 24 is located in.

the axis of the cross-shaped insulator I8 and is held therein by a tie wire 25. A iilamentary cathode 26 having electron emitting properties is preformed in theV shape of an 'M and the ends 'thereof are clamped in the Vhooks 22 and welded thereto while the center point isconnected to the hook 24. This construction eliminates strains and stresses on the fragile iilament due to high temperature treatments to which `the iilamentr is subjected during manufacture. The fine wire hooks are -not liable to any bending force since they are arranged in line With the filament while the connecting wires are heavy and overcome any strain due tov bending. A control electrode or grid surrounds the iilamentary cathode 26 and is formed of two upright Wires'21 and'28 around which is wound a helicalwire`29 in `a form so that the consecutive turns Vlie in parallel planes on' opposite sides ofthe cathode `26.V The supporting wires of the grid are disposed in the cross-shaped insulator I8 as shown in Fig. 4 with the supporting wire 2l iitting in a slot 30 while the supporting wire 28 extends through an aperture on the opposite side of the insulator arm, this Wire extending below the insulator and having a tie wire 3 IV connecting it to the anchor wire I inthe press I2.

The anchor wires in the press ofthe stem also function as the leading-in wires for the cathode 'and the grid in which'the anchor wire I5 is connected to the grid by the tie wire 3| and the anchor YWires I6 and II which are disposed at the opposite end of the press I2 convey current to the ends of the cathode 26. The purpose oi' segregating the anchor wire l5 from the other anchor wires is to provide a path of high resistance between the grid leading-in wire and the filament leading-in wires so that the heating current iield of the filament will not affect the control characteristics ofthe grid. The grid leading-in wire is 'further protected in the stem II by a tubular glass member 32 which surrounds this wire.

Onev of the features of this invention relates to the bracing of the electrode unit which forms the main supporting Vstructure of the electrodes andthis arrangement consists of twin pairs of arms, braces, or support wires 33, 34, 35 and 36 which are secured Vat their lowermost'ends to a metallic band or collar 3l which is clamped around the stem II and prevented from sliding thereon by an inner lining of wire mesh 38. The upper limbs of each pair of arms are bent in converging angles as shown more clearly in Fig. 3, with the extreme ends bent horizontally to form contraposed prongs 39, 48, 4I and 42. The next step in the assembly is to mount the anode in the Velectrode unit and this is accomplished by placing 4the anode 43 which, for practical reasons, is made of asolid block of graphite machined into substantially elliptical form with parallel sides -to correspond with the shape of the grid which itsurrounds. The anode is also formed with integral longitudinal angeportions 44 and 45 which project `outwardly on opposite sides of the flat portions of the anode. Each of the iianges is .provided'with' a vlongitudinal bore to receive an `internal supporting rod 46 which passes through an'insulating bushing 4Isituated between the anode and the insulator I8. In mounting the anode in position, it is necessary to spread the `upright braces, such as the pairs of rods 33, 34, `35 'and Y36, in order that the flange of the anode may'clear the projecting prongs of the braces and when the anode is seated on Vthe bushing 4l, the prongs 39, '40,`4I and 42 spring into a transverse 'aperture 'or socket 48, as shown clearly in Fig. 5,

fa `Acorresponding manner to the support rod extending through the ange 45 and to the brace lrods'35 and36, It Willbe noted that'the truss members 49 and 50 are attached to the support rods and braces at points such that the truss members are out of contact with the bottom surface of the insulator spacer I8. The purpose of 'this'arrangement isto permit 4expansion of the supportingstructure and 4anode during high temperature Vheat treatment without distorting Vthe filament" connections Vor causing insulator fracture. The long braces which are made of steel or iron to reduce manufacturing cost of the device are necessarily elongated during heat treatment and the clearance provided between the truss members and the insulator permits the structure to expand without straining the insulator or the filament connections in the stem. The braces or converging arms of the supporting structure tend to exert a compression force on the sides of the flanges and the truss members maintain the braces in intimate contact Vwith the flanges and Yat the same time increase the rigidity of the support by the bisecting connections with the internal support rods within the anges.

Due to the fact that the anode is formed of frable material which easily cracks or chips, the least strain placed upon this material is apt to crack the anode and render it useless. In order tol overcome this effect and lend a certain amount of resiliency to the combined structure, the interna] support rods are adapted to yield to a bending stress or strain due to shock without causing cracks to occur in the anode and also to reduce the peak of the shocks which endanger the fragile filament. In one form, the bores in the flangeslll and are enlarged in diameter as shown at 5I in Fig. 2 for about one-third the distance at the lower end of the flanges. The enlargement of the bores eliminates strains in the friable anode in a region where they are apt to occur, namely, at the juncture of the anode with the bushing 4'! and the insulator I8. At the top of the anode structure, spacing bushings 52 are arranged on the internal support rods 46 and another Across-shaped insulator 53 rests on the bushings 52 and is held in position by short stub wires which are welded to the support rod 46 extending through the flanges of the anode. The transverse arm of the insulator 53 lies parallel with the press I2 and a similar arm of the insulator I8 and is provided with an aperture to receive the upright rod 28 of the grid and the upright rod 2'! in a slot which is in alignment with the slot 3B in the insulator I8. In line with the grid supports in the insulator arm are two helical tension springs 54 through which extend hooks 55 to engage the loops of the cathode 25 and after applying a suitable tension thereto the hooks are welded to the Across-piece of the tension springs 54 to complete the assembly. Current is supplied to the anode through a suitable lead-in wire 56 which is sealed through the side of the stem II and connected to the brace or support rod 34. In this arrangement, the current is supplied to the anode through a metallic connection which is 'frictionally in contact with the anode. v

Due to the large mass of the anode, it is preferable during the evacuation process to outgas the anode by heating it by the high frequency induction method. In this method, a coil surrounds the exterior of the vessel I0 and generates a high frequency current which induces a magnetic field in the closed contour of the anode to heat it to such a high temperature to deprive it of gases and deleterious matter which might impair the Vacuum of the device. In following this method, it is extremely difficult to localize the heating to the anode alone and it is evident that if 'a surrounding metallic mass is adjacentv the stem II Y and within the eld of the heating coil, then the stem will be subjected to unnecessary heating which mightfracture the glass. Therefore, the arrangement of the narrow collar 37 on the supporting structure of the electrode assembly and the removal of this collar away from the field which might be established in the vicinity of the anode obviously relieves the stem from any excessive strains due to heating. While the narrow band or collar is employed to avoid the labove effects of heating the stem, the large mass of the electrode unit might not be effectively supported in rigid position simply by this remote connection to the stem. Therefore, in accordance with this invention the main supporting structure of the electrode unit is supplemented by an intermediate anchoring arrangement in the top of the press to insure rigidity in the assembled structure and to overcome strains or shocks imparted exterior to the device.

Another advantage in the combined structure of the electrode unit on the stem is the arrangement of the anchor rods or leading-in Wires in the stem which project through the lower spacer insulator and exert a dampening effect on shocks applied to the device. Any shock or sudden impact upon the glass vessel of the device produces a bending impulse in which the peaks of the shocks cause the greatest damage due to the straining of the yielding part beyond its elastic limit. Consequently, a support or rod may be bent to a permanent set which will cause misalignment and wide variation in the electrodes and their spacial relation. Due to the large mass of thc anode itis apparent that a shock to this element causes a movement of the whole electrode structure and the peak of the shock is liable to' the device is not rendered inoperative, provided the nlament and glass vessel remain intact, because any bending strain on the anchors will not alter the spacial relation of the electrodes since all three anchor wires will bend in the same direction below the insulator. The bending of the anchor wires merely changes the position of the electrode unit with respect to the stem and no change in spacial relation is produced between the cooperating electrodes. Therefore, it is apparent that the device of this invention can withstand extreme operating usage without endangering the efficiency and operating characteristics thereof.

While the brace supports of the main supporting structure of the electrode unit are shown as separate pairs of arms, it is equally within the scope of this invention to form the braces integrally and bend them in the form shown. Similarly, other changes may be made in the details of the assembly without departing from the scope of this invention as dened in the appended claims.

What is claimed is:

l. Ina discharge device, a stem, an anode hav- 7o" having free end portions thereof extending intov said flange, and a truss member connecting said upright members.

, right @rieles members,

2. InV a Ydischarge device, an anode havingl a flangeu portion, a support therefor comprising upright v'members with upper limbs converging towards said'flange and having portions thereof extending into said flange. a truss member connesting said upright members, and arod passing through said flange and connected to said truss member.

3. In a discharge device, an anode formed of a homogeneous refractory mass, and a metallic support therefor including pairs of individual converging arms extending into said Ymass from opposite linear directions for applying a compression force to the surface oi said anode at to the axis of said anode.

Li. In an electron discharge device, an electrode mount comprising a hollow anode having integral flange portions, insulating spacer members at opposite ends of said anode, a plurality of electrodes within said anode held by said spacer and a supporting structure for said anode, said structure having converging braces projecting into said flange portions at a medial point. 1

5. An electron discharge device comprising a hollow anode having integral flange portions, insulating spacer members at opposite ends of said anode, a plurality of electrodes within said anode and` carried by said spacer members, and a supporting structure for said anode, said structure having a pair of braces in contact with'said anode at a medial point to rigidly securersaid anode to said supporting structure.

6. In an electron discharge device, an anode, a support therefor comprising converging arms and a connecting truss member, said arms contacting with the center portion of said anode, said truss iember connecting said arms beyond one end of said anode, and a longitudinal rod extending through said anode and connected to said truss member,

7. An electron discharge device comprising a graphite anode of Ahollow configuration having diametrically opposed longitudinal flange portions, supports extending through said ange portions, a spacing insulator imember extending across each end of said anode and secured thereto by said supports, a plurality of cooperating electrodes within said anode and carried by said insulating member at each end, a pair of support braces for each flange portion having fork ends projecting into the sides of the flange portions, and a truss member attached to each of said supports and said braces to apply a compression force to said braces.

8. VAn electrode mount comprising a hollow graphite anode having integral longitudinal flange portions, said flange portions being provided with bores enlarged over a part of the length of the bores, supporting members extending through said bores, spacing insulator plates carried by said members at opposite ends of said anode, said supporting members having portions spaced from said enlarged parts of said bores, and a plurality of cooperating electrodes within said hollow anode and carried by said plates.

9. An electrode mount comprising a hollow electrode having a protruding portion on opposite sides thereof, a rigid rod extending through the portions, convergent braces extending towards said electrode on opposite sides of each of said protruding portions and engaging therewith intermediate the ends of said portions, and a truss member connected to each of said rigid ausi-,37a

a, compression. force v onf said protruding portions.

lofAnelectrondischarge device rcomprising a vessel-having a stem, an electrode assembly supported, beyond said stem including a hollow anode ofV large mass having apertured integral side flanges, connecting members extending through` said ilanges, a spacing member secured to said` connectingv members` at one end of said anode, a cathodeloc'ated within said anode and spaced therefrom by said spacing member, a pluralityof supportsextending from said stem, the

endportlons offsaidsuppor'ts being bent at anglesV converging toward said flanges, and'means connectedvto said supports compressing said supportsinto the surfaceof said flanges.

11. An electronV discharge device comprising an enclosing vessel having a stem, an electrode unit beyond .said stem including a graphite anode of substantially elliptical form with parallel sides and integral flangek portions projecting from the parallel sides, 4said'iangeportions having a longitudinal bore and a central transverse bore, spacinginsulators,at opposite ends of said anode, connecting rods threaded through each longitudinal bore and supporting said insulators, a cathode. and a grid Within said anode and supported by said spacing insulators, and a supporting structure extending from said stem and including cooperating pairs of arms, each pair having forlcends extending into said transverse bore to support said anode from said stern.

l2. An electron discharge device comprising an enclosing vessel having a stem terminating in a press, an electrode unit extending beyond said press, said unit including a hollow graphite anode having integral flange portions, spacing insulatingA plates at opposite ends of said anode, a cathode and a grid within said anode and supported Vthe plane of said press, parallel frame members extending from said stern` in parallel relation to said wires, and an electrode unit mounted beyond said press including an insulating spacer between said unit and press, said spacer being cruciform in4 shape and supported in a transverse plane by` said wires and frame members, said frame members having extensions engaging the side surfaces of one of said electrodes for reinforcing said electrode unit against shocks directed against the end of said vessel remote from said stern.

lli.Y An electron discharge device comprising an enclosing vessel having a stem terminating in a press, rigid wires extending from said press, a plurality of electrodes beyond said wires and press, a multi-arm insulating spacer for said electrodes adjacent said press, said wires being rigidly attached to the arms of said spacer in the planev of said press, and frame supports arising from said stem and interconnected with other arms ci said spacen'said supports having extensions engaging one of said electrodes.

JAMES E. CLARK. VICTOR L. RONCI.

rods and said.' braces whereby s aid braces exert 

